Manufacture of hollow metal rods, bars, and the like



F. LLOYD. MANUFACTURE OF HOLLOW METAL RODS, BARS, AND THE LIKE. APPLICATION FILED DEC.27. I917.

1,364,565. Patented Jan. 4,1921.

UNITED STATES PATENT OFFICE.

FBEDERIC LLOYD, OF SHEFFIELD, ENGLAND, ASSIGNOR TO DUNFORD AND ELLIOTT (SHEFFIELD) LIMITED, OF SHEFFIELD, ENGLAND.

MANUFACTURE OF HOLLOW METAL RODS, BARS, AND THE LIKE.

Specification of Letters Patent.

Patented Jan. 4, 1921.

To aZZ whom it may concern:

Be it known that I, FREDERIC LLOYD, a subject of the King of Great Britain, residing at 26 Alma street, Sheffield in the county of York, England, in the Kingdom of Great Britain, have invented certain new and useful Improvements in or Relating to the Manufacture of Hollow Metal Rods, Bars, and the like, of which the following is a specification.

In the manufacture of hollow metal rods, bars and the like, it is usual to form a billet or ingot of steel with a central hole which is filled with sand or other suitable material to serve as a core and the ends of the hole are stopped or plugged. The billet or ingot is then heated and submitted to repeated rolling operations until a. rod or bar of the required dimensions is obtained, after which the plugged ends are severed and the core removed. With the methods already in practice various ob'ections revail, inasmuch as the plugs used or the c osing of the ends of the central hole often break away, or are forced out and allow the core to escape. In some instances the plugs become sheared off during rolling, or they become expanded lengthwise within the hole to such an extent that considerable portions of the ends of the rolled bar or rod are of necessity required to be cut away, thus involving a large amount of waste.

The present invention has for its chief object to overcome these defects by means of plugs which will enable the waste to be considerably reduced and also enable the ends of the central hole to be effectively sealed without risk of the plugs becoming detached from the billet or ingot during the rolling operations.

According to the invention the plug is of such a character that when applied to each end of the central hole in the billet or ingot and subjected to compression during the rolling operation, it will contract or collapse within the central hole and become extended therein to an extent considerably less than heretofore and without becoming disconnected from the billet or ingot. For this purpose the plug may consist of a resilient plate or disk of steel or other metal slightly larger in diameter than that of the hole in the billet and of wavy, corrugated or similar form in transverse section the corrugations being preferably annular.

In order that the invention may be clearly understood and readily carried into effect the same will now be more fully described by the aid of the accompanying drawing in which Figure l is a perspective view and Fig. 2 is a sectional view of the preferred form of plug.

Fig. 3 is a fragmental view of one end of a billet or ingot in section showing the lug in position preparatory to rolling the billet.

Fig. 4 is a similar view to Fig. 3 showing the end of the bar after the rolling operations have been completed and the bar reduced to the required dimensions.

a is the plug which in the example shown consists of a circular plate of approximately (three-thirty-seconds) of an inch in thickness having a central corrugation a extending outwardly and surrounded by a shallow annular corrugation (1. the central corrugation a protruding outward beyond the plane containing the edge of periphery a of the plug. The depth of the channel or channels formed by the corrugations a, a is so chosen that the plate or disk at will collapse or become folded radially inward, under the compression exerted during the rolling operations, in such manner that the longitudinal extension of the plug inwardly Wlll be considerably reduced. The resilient nature of the plug enables it to be forced into place so that the outer edge or periphery a will firmly grip the interior of the hole I) in the billet or ingot b (Fig. 3) the plug a being finally secured in position by electrically or otherwise welding the edge or periphery a to the margin of the hole prior to the rolling operations. It will be understood that a plug is forced into place at one end of the hole in the billet or ingot and the hole then filled with the sand or other material constituting the core a, then another similar plug is forced into the end of the hole by which the sand was introduced, the said plugs remaining in position by their resiliency and being subsequently welded in place. The necessity of welding one of the plugs in position prior to the filling of the hole with the sand 'as hitherto is thusavoided. Furthermore, as the edge or periphery of the plugs is bounded and sup-. ported by the margin of the hole in the billet or ingot, shearing of the welded joints by the contraction of the billet or ingot during the rolling operations is also avoided.

The resilient plugs may be driven into the.

ends of the hole in the billet or ingot by means of a punch-like tool appropriately formed to engage the depressed portion or portions .of the corrugations near the periphery of the plugs.

Although preferring the plug a to fit the hole 6 in the manner indicated it Will be understood that the size of the plug may be such as to provide a neat or loose fit and be secured to the billet b by the Welding process.

What I claim and desire to secure by Let ters Patent of the United States is 1. The combination With a hollow ingot or billet, of. a core therein, and plugs closing the end of the bore in the billet or ingot and each consisting of a resilient metal plate having its edge secured to the surrounding wall of the billet or ingot.

2. The combination With a holloW ingot or billet, of a core therein, and plugs closing the ends of the bore in the billet or ingot and each consisting of a resilient metal disk having its edge Welded to the surrounding Wall of the bore in Which it is placed.

3. The combination With a hollow ingot or billet, of a core therein, and plugs closing the ends of the bore in the billet or ingot and each consisting of a resilient metal disk of corrugated form in cross section having its edge secured to the surrounding Wall of the billet or ingot.

4. The combination with a hollow ingot or billet, of a core therein, and plugs clos ing the ends of the bore in the billet or ingot and each consisting of a compressed resilient metal disk and of corrugated form in cross section, the peripheral edge of each disk being permanently secured to the surrounding Wall of the billet or ingot.

FREDERIC .JLOYD. 

